EP0129721A2 - Magnetische Aufzeichnungsmaterialien - Google Patents

Magnetische Aufzeichnungsmaterialien Download PDF

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Publication number
EP0129721A2
EP0129721A2 EP84105933A EP84105933A EP0129721A2 EP 0129721 A2 EP0129721 A2 EP 0129721A2 EP 84105933 A EP84105933 A EP 84105933A EP 84105933 A EP84105933 A EP 84105933A EP 0129721 A2 EP0129721 A2 EP 0129721A2
Authority
EP
European Patent Office
Prior art keywords
magnetic
coating
lubricant
additive
magnetic recording
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP84105933A
Other languages
English (en)
French (fr)
Other versions
EP0129721A3 (en
EP0129721B1 (de
Inventor
Ming Ko
Michael Eugene Oxsen
Robert Bruce Prime
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of EP0129721A2 publication Critical patent/EP0129721A2/de
Publication of EP0129721A3 publication Critical patent/EP0129721A3/en
Application granted granted Critical
Publication of EP0129721B1 publication Critical patent/EP0129721B1/de
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/84—Processes or apparatus specially adapted for manufacturing record carriers
    • G11B5/842—Coating a support with a liquid magnetic dispersion
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
    • G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
    • G11B5/702—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the bonding agent
    • G11B5/7028—Additives, e.g. crosslinking agents
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/90—Magnetic feature
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249978—Voids specified as micro
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249978—Voids specified as micro
    • Y10T428/24998—Composite has more than two layers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249986—Void-containing component contains also a solid fiber or solid particle
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31551—Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
    • Y10T428/31609—Particulate metal or metal compound-containing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31855—Of addition polymer from unsaturated monomers
    • Y10T428/31931—Polyene monomer-containing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31855—Of addition polymer from unsaturated monomers
    • Y10T428/31935—Ester, halide or nitrile of addition polymer

Definitions

  • the invention relates to magnetic recording materials or compositions.
  • a magnetic recording device such as a magnetic disk, has a magnetic layer which includes a thermosetting or thermoplastic organic binder system and magnetic particles such as iron oxide.
  • the organic polymer matrix containing the magnetic particles is applied to the disk in solvents at a given thickness and cured to a tough durable film.
  • lubricant retention of a particulate disk coating formulation can be attributed to two separate processes; retention of lubricant within microroughnesses near the surface of a disk, and retention of lubricant in microvoids distributed throughout some thickness of the coating.
  • retention of lubricant attributed to the surface process is fairly constant as a function of different disk coating formulations, while that attributed to the microvoid process varies from coating batch to coating batch.
  • this variance of lubricant retention as a function of microvoid density occurs as a result of different levels of phase separation of an organic constituent of the coating plus different levels of oxidative degradation volatilization during cure.
  • the present invention is directed to the use of polymeric additives in a magnetic coating composition, which, due to their ability to phase separate and their inherently lower thermal oxidative stability in relation to the magnetic coating binder system, result in additional microvoid formation from the same process ascribed to the current thermal oxidative degradation volatilization mechanism.
  • these polymer additives produce increased durability of the magnetic coating if they are selected so as not to be 100% thermally oxidized during coating cure.
  • the invention provides a method of fabricating a magnetic recording element comprising applying a layer of a flowable magnetic material to a substrate, said material comprising magnetic particles dispersed in a curable binder; curing the magnetic material of the applied layer; and thereafter applying a lubricant to the surface of the magnetic layer; said method being characterised by the step of adding a thermally degradable additive to the flowable magnetic material, said additive being degraded during curing of the material and producing a plurality of microvoids in the surface of the layer capable of enhancing retention of the lubricant on said surface.
  • the invention also provides a magnetic recording element having a substrate and a magnetic coating on said substrate, said coating having been applied to said substrate in the form of a liquid comprising magnetic particles dispersed in a curable binder which was thereafter cured and a lubricant applied to the surface of the cured magnetic coating, said element being characterised by the improvement comprising an additive in said coating, said additive being thermally degradable during curing of said magnetic coating and prior to application of said lubricant to produce a plurality of microvoids in the surface of said magnetic coating to enhance retention of said lubricant on said surface.
  • Performance of the present invention involves the selection of a proper polymeric additive or combination of additives to achieve the optimum improvement in both lubricant retention and coating durability.
  • the polymeric additive or additives are selected so as to be 100% thermally oxidizable during coating cure, this will result in a maximum increase in microvoid formation to enhance lubricant retention, but it will have little or no effect on increased coating durability from the presence of the polymeric additive since all of the additive has oxidized from the coating.
  • the polymeric additive or additives are selected so as to undergo substantially no thermal oxidation during coating cure, this will have a maximum effect on improved coating durability because of the lubricating qualities of the additive or additives, but will have little or no effect on microvoid formation for increased lubricant retention.
  • polymeric additives which are useful in practicing the present invention are the following, either alone or in combination:
  • the unique properties of the current invention stem from the use of polymeric additives which thermally degrade during coating cure, volatilizing with nearly 100% efficiency if desired. This is in contrast to other polymeric additives, such as polyvinylmethylether (PVME), which is also subject to thermal oxidative degradation, but which has much lower volatilization efficiency. These differences are due to either the presence of crosslinkable pendant side chain functionality, or higher molecular weight characteristics, as in the case of PVME.
  • PVME polyvinylmethylether
  • the polymeric additives of the present invention can be used in a suitable concentration, the range preferably being from 0.5 to 5 % by weight of the magnetic pigment particles.
  • the additives may be added at a suitable stage of the coating preparation process, i.e., after ball milling, post dispersion, or filtering.
  • a matrix study designed to assay the effect of polymeric additives showed an increase in lubricant retention and abrasion resistance over a control formulation without additive.
  • Subsequent TGA of a coating batch with and without one or more polymeric additives correlated the observed increase in thermal oxidative volatilization due to the additive to the previously observed increase in lubricant retention.
  • the poly(butene) material totally degrades and volitalizes as a function of isothermal temperature. Variations on this theme can be developed by utilizing different molecular weight fractions of poly(butene) giving different rates of degradation and weight loss from 0 to 100%, depending on the desired application.
  • these materials act as sacrificial polymeric components which scavenge available oxygen from the coatings.
  • Table 1 below lists the results of lubricant retention evaluations conducted on samples of magnetic recording disks having a polyurethane coating with magnetic particles dispersed therein as described, for example, European specification No. 75083 and US specification No. 4405684.
  • the first batch of tested disks listed in column 1 contained no polymeric additive.
  • the disks in column 2 contained polybutene in an amount equal to 5% by weight of the magnetic iron oxide in the dispersion.
  • the polybutene was in the form of a compound identified as H-35 manufactured by Amoco Chemical Co.
  • Those disks listed in column 3 contained polymeric polyethylene beads manufactured under the name of XF Mekon by Western Petro Chemical.
  • Table 2 below lists a number of properties of magnetic disks formulated using a polymeric additive in accordance with the present invention as compared with disks not having such an additive (control formulation).
  • the magnetic coating formulation for the disks in Table 2 was an epoxy/phenolic system and the polymeric additive was H-35.
  • the coefficient of friction and film toughness were measured with a slightly modified standard ASTM pin-on-disk shear tester. A measure of the efficiency of these solid lubricants was performed with a shear tester with a shear force of 20 grams applied to the disk surface through reciprocating stainless steel balls of 1/8 in. diameter. The reciprocal force applied to the disk provides the measurement of coefficient of friction and number of cycles to deplete the coating surface and eventually tear up the coating to the bare substrate. When these disks were coated with an extra layer of lubricant on the surface, they all performed the same; the coefficients of friction were between 0.11 and 0.12, and film toughness was excellent. After delubricating these disks with proper solvents, the lubricant retention showed an increase of 143% with polybutene lubricant compared to the control.
  • the delubricated disks showed that the polybutene lubricant reduced the coefficient of friction, and improved toughness of the coating.
  • Lubricant retention is defined as the amount of lubricant a disk will hold which cannot be wiped off by a specific wiper at a specific pressure for a given number or duration of wipes.
  • This table shows not only the marked increase in lubricant retention available with the present invention, as does Table 1, but also shows the significant increase in coating durability brought about by the lubricating properties of the polymeric additives, as measured by the difference in coating durability of the unlubricated disks having a polymeric additive therein and that of the unlubricated disks of the control formulation.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Magnetic Record Carriers (AREA)
  • Paints Or Removers (AREA)
EP84105933A 1983-06-27 1984-05-25 Magnetische Aufzeichnungsmaterialien Expired EP0129721B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US06/508,300 US4546035A (en) 1983-06-27 1983-06-27 Polymeric additives for magnetic coating materials
US508300 1983-06-27

Publications (3)

Publication Number Publication Date
EP0129721A2 true EP0129721A2 (de) 1985-01-02
EP0129721A3 EP0129721A3 (en) 1986-09-10
EP0129721B1 EP0129721B1 (de) 1988-08-17

Family

ID=24022177

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84105933A Expired EP0129721B1 (de) 1983-06-27 1984-05-25 Magnetische Aufzeichnungsmaterialien

Country Status (4)

Country Link
US (1) US4546035A (de)
EP (1) EP0129721B1 (de)
JP (1) JPS6010419A (de)
DE (1) DE3473524D1 (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0212394A2 (de) * 1985-08-19 1987-03-04 International Business Machines Corporation Verfahren zur Herstellung einer magnetischen Aufzeichnungsplatte
DE3634692A1 (de) * 1985-10-15 1987-04-16 Hitachi Maxell Magnetische scheibe
DE3642243A1 (de) * 1985-12-10 1987-06-11 Tdk Corp Magnetische aufzeichnungstraeger und verfahren zu ihrer herstellung
DE3801877A1 (de) * 1987-01-23 1988-08-04 Hitachi Ltd Magnetischer datentraeger und herstellungsverfahren dafuer

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8402136A (nl) * 1984-07-05 1986-02-03 Pd Magnetics Bv Magnetisch registratie element en methode voor de vervaardiging ervan.
JPS6173237A (ja) * 1984-09-18 1986-04-15 Hitachi Maxell Ltd 磁気デイスク
US4626463A (en) * 1984-09-26 1986-12-02 Minnesota Mining And Manufacturing Company Diskette having wear-resistant magnetizable layer
US4596739A (en) * 1985-02-11 1986-06-24 International Business Machines Corporation Rigid magnetic recording media
US4769166A (en) * 1987-06-01 1988-09-06 United Technologies Automotive, Inc. Expandable magnetic sealant
US6013531A (en) * 1987-10-26 2000-01-11 Dade International Inc. Method to use fluorescent magnetic polymer particles as markers in an immunoassay
DE3736998A1 (de) * 1987-10-31 1989-05-11 Basf Ag Magnetischer aufzeichnungstraeger
EP0380710A1 (de) * 1988-12-24 1990-08-08 International Business Machines Corporation Verfahren zur Erhöhung des Schmiermittelaufnahmevermögens bei Magnetplatten
JPH03116413A (ja) * 1989-09-28 1991-05-17 Fuji Photo Film Co Ltd 磁気記録媒体
JPH06314446A (ja) * 1992-06-19 1994-11-08 Tdk Corp 光磁気ディスク

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2533850B2 (de) * 1974-07-30 1977-08-18 Eastman Kodak Co, Rochester, N.Y. (V.St.A.) Magnetisches aufzeichnungsmaterial sowie verfahren zur herstellung desselben
DE2710777A1 (de) * 1976-03-12 1977-10-06 Eastman Kodak Co Magnetisches aufzeichnungsmaterial
DE2833845A1 (de) * 1977-08-05 1979-02-15 Toyo Boseki Magnetisches aufzeichnungsmaterial
DE2848919A1 (de) * 1977-11-10 1979-05-17 Sony Corp Magnetische speichermedien
JPS5862826A (ja) * 1981-10-12 1983-04-14 Toray Ind Inc 磁気記録媒体用ポリエステルフイルム
DE3341205A1 (de) * 1982-11-15 1984-05-17 Hitachi, Ltd., Tokio/Tokyo Magnetscheibe und verfahren zu deren herstellung

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53141003A (en) * 1977-05-16 1978-12-08 Hitachi Ltd Production of magnetic disc
US4267238A (en) * 1979-12-18 1981-05-12 Minnesota Mining And Manufacturing Company Flexible magnetic recording media lubricated with fluorinated telechelic polyether polymer
US4268556A (en) * 1979-01-08 1981-05-19 Minnesota Mining And Manufacturing Company Rigid magnetic recording disks lubricated with fluorinated telechelic polyether
JPS563435A (en) * 1979-06-20 1981-01-14 Fujitsu Ltd Manufacture of magnetic recording medium
DE3024918A1 (de) * 1979-07-02 1981-01-22 Fuji Photo Film Co Ltd Magnetisches aufzeichnungsmaterial und verfahren zu dessen herstellung
JPS5625232A (en) * 1979-08-06 1981-03-11 Sony Corp Magnetic recording medium
DE3113859A1 (de) * 1980-04-07 1982-01-28 Fuji Photo Film Co., Ltd., Minami-Ashigara, Kanagawa Magnetisches aufzeichnungsmaterial
JPS57135441A (en) * 1981-02-13 1982-08-21 Sony Corp Magnetic recording medium
JPS57164436A (en) * 1981-04-02 1982-10-09 Fuji Photo Film Co Ltd Manufacture of magnetic recording medium
US4405684A (en) * 1981-09-21 1983-09-20 International Business Machines Corporation Rigid magnetic coating composition with thermosetting binder for hard file

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2533850B2 (de) * 1974-07-30 1977-08-18 Eastman Kodak Co, Rochester, N.Y. (V.St.A.) Magnetisches aufzeichnungsmaterial sowie verfahren zur herstellung desselben
DE2710777A1 (de) * 1976-03-12 1977-10-06 Eastman Kodak Co Magnetisches aufzeichnungsmaterial
DE2833845A1 (de) * 1977-08-05 1979-02-15 Toyo Boseki Magnetisches aufzeichnungsmaterial
DE2848919A1 (de) * 1977-11-10 1979-05-17 Sony Corp Magnetische speichermedien
JPS5862826A (ja) * 1981-10-12 1983-04-14 Toray Ind Inc 磁気記録媒体用ポリエステルフイルム
DE3341205A1 (de) * 1982-11-15 1984-05-17 Hitachi, Ltd., Tokio/Tokyo Magnetscheibe und verfahren zu deren herstellung

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
IBM TECHNICAL DISCLOSURE BULLETIN, vol. 26, no. 9, February 1984, page 4455, New York, US; M. R. LORENZ et al.: "Controlled pore formation in Magnetic disk coatings to optimize lubricant retention" *
PATENT ABSTRACTS OF JAPAN, vol. 7, no. 152 (P-208)[1297], 5th July 1983; & JP - A - 58 62826 (TORAY) 14-04-1983 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0212394A2 (de) * 1985-08-19 1987-03-04 International Business Machines Corporation Verfahren zur Herstellung einer magnetischen Aufzeichnungsplatte
EP0212394A3 (en) * 1985-08-19 1989-02-15 International Business Machines Corporation A method of making a magnetic record disk
DE3634692A1 (de) * 1985-10-15 1987-04-16 Hitachi Maxell Magnetische scheibe
DE3642243A1 (de) * 1985-12-10 1987-06-11 Tdk Corp Magnetische aufzeichnungstraeger und verfahren zu ihrer herstellung
US4759954A (en) * 1985-12-10 1988-07-26 Tdk Corporation Magnetic recording medium and preparation
DE3642243C2 (de) * 1985-12-10 1998-07-09 Tdk Corp Verfahren zur Herstellung eines magnetischen Aufzeichnungsträgers
DE3801877A1 (de) * 1987-01-23 1988-08-04 Hitachi Ltd Magnetischer datentraeger und herstellungsverfahren dafuer

Also Published As

Publication number Publication date
EP0129721A3 (en) 1986-09-10
DE3473524D1 (en) 1988-09-22
EP0129721B1 (de) 1988-08-17
JPS6010419A (ja) 1985-01-19
US4546035A (en) 1985-10-08

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